I too am thinking about getting a tandem for the wife and I. We have the same size disparity. I'm 6'0", she is 5'0". I am currently looking into a Trek T900. It's listed as having 18.5"/14.5" seattubes. Unforutnately, if I want this particular bike, I would be getting it without either of us actually test riding it. Does anyone know if this bike should be able to fit us? We are planning to use it for very casual riding on roads and bike paths doing distances of usually not more then 30 miles or so.